56 FISHES OF ILLINOIS 



CRISTIVOMER NAMAYCUSH (Walbaum) 



GREAT LAKE TROUT 



Walbaum, 1792, Artedi Piscium, 68 (Salmo). 



G., VI, 123 (Salmo); J. & G., 317 (Salvelinus) ; M. V., 80 (Salvelinus) ; J. & E., I, 

 504; N., 44 (Salmo); J., 54; F., 73 (Salvelinus); L., 21. 



Length 3 feet; body elongate, depth 4 in length. General coloration 

 dark grayish green to brownish, sometimes paler, sometimes almost black; 

 everywhere with rounded paler spots, which are often yellowish or reddish 

 tinged; head usually vermiculate above; dorsal and caudal reticulate with 

 darker, the anal faintly so. Head 43^ long, and its upper surface flattened; 

 eye 4i^ in head; interorbital space 33^; nose 33^; mouth very large, the 

 maxillary extending much beyond eye, nearly half length of head; teeth very 

 strong. Dorsal rays 11; anal 11; caudal well forked. Scales very small, 185 

 to 210 in longitudinal series; lateral line continuous, pores about 100. 



This magnificent species, one of the three most important 

 fishes of our Great Lakes is, hke the whitefish, a species of 

 northern distribution. It is found throughout the Great Lake 

 region, and in the lakes of New York, New Hampshire, and 

 Maine, thence to the headwaters of the Columbia and Fraser 

 rivers and the streams of Vancouver Island, and northward to 

 the arctic circle. It is common in the northern part of Lake 

 Michigan, but rarer to the southward. In our Illinois markets 

 it is known almost wholly by the name of lake trout, but farther 

 north the names of Mackinaw trout, salmon-trout, and namay- 

 cush are sometimes used. It is extremely variable in size, form, 

 and color, particularly under the influence of local conditions, 

 and hence has received many local names. 



Although the usual weight of specimens taken in large- 

 meshed gill-nets is about eight pounds, and of those captured 

 with lines and seines not more than two pounds, the species is 

 said by Goode to attain a weight of a hundred and twenty 

 pounds, which is eight times the maximum size of the closely 

 allied brook trout. ''This is due, perhaps," he saj^s, *'to the 

 greater ea^e with which, for hundreds of generations, the lake 

 trout have obtained their food. They are almost always found 

 in the same lakes with one or more kinds of whitefish, whose 

 slow helpless movements render them an easy prey, and upon 

 whose tender luscious flesh the lake trout feeds voraciously." 

 This trout is a fish of highly predaceous habit, living especially 

 upon lake herring of all sizes, but eating, in an emergency, 

 almost any animal food which comes in its way. 



